Marking pen



FIG. 1 is a top right front perspective view of a marking pen showing my new design;

FIG. 2 is a front elevational view;

FIG. 3 is a top plan view;

FIG. 4 is a right side elevational view, the left side being a mirror image thereof;

FIG. 5 is a bottom plan view;

FIG. 6 is a rear elevational view; and,

FIG. 7 is a perspective view with the cap member in a stored position. 

The ornamental design for a marking pen, as shown and described. 